docs: def visit_classdef(self, node):
          """Class visitor."""
          if not node_is_subclass(node, 'django.forms.models.ModelForm', '.ModelForm'):
              # we only care about forms
              return
  
          meta = _get_child_meta(node)
  
          if not meta:
              return
  
          for child in meta.get_children():
              if not isinstance(child, Assign):
                  continue
  
              if child.targets[0].name == 'exclude':
                  self.add_message('W%s04' % BASE_ID, node=child)
                  break